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In liquid chromatography, the mobile phase velocity is taken as the exit velocity, that is, the ratio of the flow rate in ml/second to the cross-sectional area of the ‘column-exit flow path.’ For a packed column, the cross-sectional area of the column exit flow path is usually taken as 0.6 times the cross-sectional area of the column.
Chromatographic peak resolution is given by = + where t R is the retention time and w b is the peak width at baseline. The bigger the time-difference and/or the smaller the bandwidths, the better the resolution of the compounds.
A chemist in the 1950s using column chromatography. The Erlenmeyer receptacles are on the floor. Column chromatography in chemistry is a chromatography method used to isolate a single chemical compound from a mixture. Chromatography is able to separate substances based on differential absorption of compounds to the adsorbent; compounds move ...
The valley definition defines ΔM as the closest spacing of two peaks of equal intensity with the valley (lowest value of signal) between them less than a specified fraction of the peak height. Typical values are 10% or 50%. The value obtained from a 5% peak width is roughly equivalent to a 10% valley. [1]
The peak is "well-sampled", so that less than 10% of the area or volume under the peak (area if a 1D Gaussian, volume if a 2D Gaussian) lies outside the measurement region. The width of the peak is much larger than the distance between sample locations (i.e. the detector pixels must be at least 5 times smaller than the Gaussian FWHM).
(For instance, if the first column offers a peak capacity (k 1)of 100 for a 10-minute separation, and the second column offers a peak capacity of 5 (k 2) in a 5-second separation, then the combined peak capacity may approach k 1 × k 2 =500, with the total separation time still ~ 10 minutes). 2D separations have been applied to the analysis of ...
Elution principle of column chromatography In analytical and organic chemistry, elution is the process of extracting one material from another by washing with a solvent: washing of loaded ion-exchange resins to remove captured ions , or eluting proteins or other biopolymers from a gel electrophoresis or chromatography column .
where Δi p is the differential current peak value, A is the surface area of the electrode, C 0 * is the concentration of the species, D 0 is the diffusivity of the species, t p is the pulse width, and ΔΨ p is a dimensionless parameter which gauges the peak height in SWV relative to the limiting response in normal pulse voltammetry. [4]